Inhalation device

ABSTRACT

The present invention relates to a device for providing an aerosol flow, an air flow or both with at least a compressor for providing an air flow, a nebulization device for generating an aerosol flow and a mixing means for optionally mixing the aerosol flow with the air flow to provide a total flow, wherein the total flow is composed of the aerosol flow, the air flow or both. Further, the device comprises at least a first air channel between the compressor and the nebulization device, at least a second air channel between the compressor and the mixing means and an amplification means for increasing the air flow provided by the compressor.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to European Application No. 07115812.5,filed Sep. 6, 2007 and entitled INHALATION DEVICE, which is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The invention relates to a device for providing an aerosol flow and/oran air flow and in particular an inhalation device.

BACKGROUND

Inhalation, i.e., the therapeutic inhalation of aerosol, turned out tobe an effective and gentle method for the treatment of variousrespiratory diseases such as for example acute respiratory disease,chronic obstructive pulmonary disease, and in particular bronchialasthma. Moisturizing the mucous membranes with an aerosol of finedroplets causes dissolving of the mucus in the airways and therebyfacilitates the coughing up secretion. Additionally inhaledpharmaceuticals can be applied systematically into the bronchi or thelung where they are effective for the treatment of a topical or systemicdisease. Conventionally a nozzle nebulizer is used to provide theaerosol, the nebulizer atomising the active pharmaceutical ingredientusing a compressor and a nebulizing nozzle. The penetration depth of theatomized droplets into the lung depends, i.e., on the size of thedroplets. Moreover, the specific effect of the droplets can becontrolled in that nebulization is only performed during the inhalationprocess for a certain period of time.

Thus, inhalation devices where the nebulization process can becontrolled, depending on the inhalation or exhalation phase, have beenreported. German Patent No. 199 39 417 A1, e.g., describes an inhalationdevice with a control means in which a pneumatic valve is controllabledepending on an inhalation phase, an exhalation phase and a rest period.These phases can be determined by a pressure sensor. A further automatedinhalation device is described in EP 1 700 614 A1. This documentdescribes a control means which controls an air pump via voltage and/orpulse width modulation to supply an inhalation flow and/or an inhalationvolume according to a predetermined chronological sequence to anebulizer connected to the air pump.

Generally it is desirable that inhalation devices are as small aspossible since chronically ill patients, in particular, often carrythese devices around. The size and weight of such devices are oftenpredetermined by the compressor. On the one hand, the compressor mustgenerate a sufficiently high enough pressure in order to operate thenebulizing nozzle and on the other hand must provide a sufficiently highair flow to meet the breathing volume per minute of the patient. Highpressure and high flows at the same time, however, require ahigh-performance compressor, which may be accordingly voluminous andheavy.

Thus, it is an object of the present invention to provide an improveddevice for providing an aerosol flow and/or an air flow. This object isachieved with the features of the claims.

SUMMARY

The present invention provides a maximum air flow with a compressor assmall as possible. Accordingly, the present invention relates to adevice for providing an aerosol flow and/or an air flow with at least acompressor for providing an air flow, a nebulization device forgenerating an aerosol flow and a mixing means for optionally mixing theaerosol flow with the air flow to a total flow, wherein the total flowis composed of the aerosol flow and/or the air flow. Furthermore, thedevice comprises at least a first air channel between the compressor andthe nebulization device, at least a second air channel between thecompressor and the mixing means and at least an amplification means forincreasing the air flow provided by the compressor.

According to a further aspect of the invention, the device has, inaddition to or instead of the amplification means, a bypass channel,which connects the first and the second air channel and is suitable forredirecting the air flow in the first air channel into the mixing meansvia bypassing the nebulization device. This bypass channel canpreferably be activated or deactivated by a valve at certain intervals,wherein a constant total flow is maintained.

In a preferred embodiment of the invention, the amplification means hasat least one Venturi nozzle. This Venturi nozzle is preferably arrangedalong the second air channel and suitable for sucking ambient air intothe second air channel, preferably via a filter. The Venturi nozzle canbe operated at a working pressure between 0.5 and 5 bar, preferablybetween 0.8 and 3 bar and particularly preferably at 1.2 to 2 bar. Thethus created air flow is in a range of 1 to 60 litres per minute. Thecompressor and the Venturi nozzle are preferably designed such that nopressure and/or flow control is necessary.

In a further preferred embodiment, two or more amplification means areprovided. Alternatively, the amplification means may comprise two ormore Venturi nozzles preferably connected in series. Thus, it is to beparticularly ensured that a sufficient flow is obtained when thenebulization device is not active. The advantage of the Venturi nozzlesconnected in series is particularly apparent in small inner diameters ofthe tubes and tubes having a length of more than 1 m. Tubes having asmall diameter and a length of more than 1 m facilitate the handling ofthe hand-held nebulizer. Tubes as used in respirators are not acceptedby the patients and increase the contamination risk since aerosoldroplets reach the air supply more easily due to the big diameters. Inthe present invention a tube having a length of 0.2 m to 2 m and aninner diameter of 1 to 20 mm can be used, preferably a tube diameterhaving an inner diameter of 2 to 5 mm and a length of 0.5 to 1.5 m isused. The Venturi nozzles are dimensioned such that for a preciselyspecified tube system with known flow resistance upon activated anddeactivated nebulizer there is exactly the same inspiration flow at themouthpiece without the necessity of the device to readjust.

The device further preferably comprises a control means which can varyor determine the aerosol flow and/or the air flow. According to theinvention, the total flow of aerosol and/or air flow is to remainbasically temporally constant. Total flow is in a range between 1 and 60litres per minute, preferably between 3 and 50 litres per minute. Thenebulization device is suitable for generating an aerosol flow of 1 to20 litres per minute, preferably 3 to 7 litres per minute andparticularly preferably about 6 litres per minute.

Moreover, the device optionally comprises at least a check valve in thesecond air channel. Further, a bleed valve is added between compressorand nebulization device. Instead of a control via a vent valve, thecompressor can be switched on or off.

It is also possible to provide the mixing means as mouthpiece to enablethe use of the device as inhalation device.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the device according to the invention areexemplarily described with reference to the Figures.

FIG. 1 is a schematic diagram of a preferred embodiment of theinhalation device according to the invention.

FIG. 2 a is a circuit diagram of the device according to FIG. 1 with theair flows occurring during the inhalation upon activated nebuliser.

FIG. 2 b is a circuit diagram of the device according to FIG. 1 with theair flows occurring during the inhalation upon deactivated nebuliser.

FIG. 2 c is a circuit diagram of the device according to FIG. 1 with theair flows occurring during exhalation.

FIG. 3 is a schematic diagram of a further embodiment of the inhalationdevice according to the invention.

FIG. 4 is a schematic diagram of a further embodiment of the inhalationdevice according to the invention.

FIG. 5 is a schematic diagram of a further embodiment of the inhalationdevice according to the invention.

DETAILED DESCRIPTION

FIG. 1 schematically shows a preferred embodiment of the deviceaccording to the invention for providing an aerosol flow and/or an airflow. The device comprises a compressor 1 for providing an air flow aswell as a nebulization device 2 for generating an aerosol flow. Thecompressor 1 and the nebulization device 2 are connected to each othervia a first air channel 4. The device further comprises a mixing means 3for optionally mixing the aerosol flow with the air flow to a totalflow. In the preferred embodiment, the nebulization device 2 and themixing means 3 are integrated in one component. However, it is alsoconceivable that the two means are provided separately and that they areconnected to each other via an air channel. In order to use the deviceas inhalation device, the mixing means is provided with a mouthpiece inthe embodiment shown.

The mixing means 3 is connected to the compressor 1 via a second airchannel 5. Thus, the air flow generated by the compressor 1 is dividedinto two partial flows passing through the two air channels 4 and 5. Inthe second air channel 5, a Venturi nozzle 6 is provided asamplification means, which serves to increase the air flow generated bythe compressor 1. The Venturi nozzle 6 sucks additional air through thefilter 7 which is then passed on through the second air channel 5 to themixing means 3. As an alternative to the embodiment shown in FIG. 1, twoor more Venturi nozzles 6 can be provided, which are preferably arrangedin series to further amplify the generated air flow.

The inlet opening for the compressor 1, too, comprises an air filter 8.The use of a Venturi nozzle is advantageous since a separate pressurerelief valve is not necessary anymore then. The Venturi nozzle replacesthe pressure relief valve by an appropriate geometry choice.Furthermore, the inhalation flow is independent of the nebulizergeometry. If, e.g., the nebulizing nozzle is too small (e.g., upon anexchange of the nebulizers), the flow via the nebulizer is getting less.However, this is automatically offset in that the flow generated by thecompressor flows via the Venturi nozzle to a greater extent. Thecompressor is designed such that together with the Venturi nozzle andthe nebulizing nozzle, an ideal working point is achieved and no controlis necessary anymore. The corresponding pressure ratios are set by thegeometrical ratios of the nozzles. According to the invention, theinhalation flow is always the same, only the inhalation volume isadjusted according to the patient.

The design shown in FIG. 1 at the same time enables the generation of asufficiently high pressure to atomize a corresponding activepharmaceutical ingredient in the nebulization device 2 by means of anebulizing nozzle in order to maintain a sufficiently high air flowwhich is adapted to the breathing volume per minute of the patient. Herethe compressor 1 provides the required pressure and the Venturi nozzle 6the sufficient flow volume. This embodiment of the inhalation devicealso involves the great advantage that a compressor can be used which isdesigned smaller in view of its performance than would actually benecessary for generating the desired pressures and flows. Thus, theinvention enables a deliberate undersizing of the compressor which savescosts and space in the housing of the inhalation device.

According to the invention, the preferred device shown in FIG. 1 furthercomprises a bypass channel 9 which can be activated or deactivated bymeans of a bypass valve 10. The bypass channel serves to bypass thenebulization device 2. It is the basic idea of the bypass channel 9 toprovide a constant total flow, wherein the nebulization can be activatedor deactivated. As explained further above, it can be advantageous tocarry out the nebulization only at times during the inhalation process.Thus, it is possible to check in which area of the bronchi or the lungsthe active aerosol is to be administered. If, however, the nebulizationis interrupted during the inhalation process, i.e., no air flows throughthe first air channel 4 anymore, the patient is not to face a reducedair flow. This problem is solved by the invention in that the bypassvalve 10 is switched such that when the nebulization device 2 isdeactivated the air flowing through the first air channel 4 isredirected into the bypass channel 9 and the second air channel 5. Thus,the total air flow generated by the compressor 1 is further onadministered into the mixing means and thus to the patient. If, on theother hand, the patient does not need the entire air flow provided bythe system, e.g., during an inhalation pause, excessive air may beemitted through the valve 11. Alternatively, the compressor 1 can besimply activated or deactivated to control the air flow.

The control or regulation of the valves 10 and 11 as well as thenebulization device 2 is carried out via a control means or CPU, whichdetects the respective phase of the breathing cycle via a pressuresensor 12 and accordingly switches the valves and the nebulizationdevice. The control means preferably further comprises a display as wellas keys for the user to enter information.

Although in the depicted embodiment of the inhalation device both theVenturi nozzle 6 and the bypass channel 9 are displayed, embodimentsonly comprising the Venturi nozzle 6 or only the bypass channel 9 arealso conceivable. Both features individually lead to the fact that acompressor 1 of lower performance can be used. In combination anaccordingly stronger effect can be achieved.

FIG. 2 a shows a circuit diagram of the device according to FIG. 1 andthe switching condition of the valves 10 and 11 as well as the air flowsoccurring during inhalation when the nebulizer is activated. Here thevalve 10 is connected such that the compressor 1 is connected to thenebulization device 2 and blocks the bypass channel 9. The valve 11 isconnected such at the same time that the compressor is connected to themixing means 3. This results in the air paths illustrated by the arrows.Accordingly air flows through the filters 7 and 8 into the Venturinozzle and the compressor and is supplied to the patient via thenebulization device 2 and the mixing means 3. The bypass channel 9 isnot used in this context. For example there is a flow of 6 l/m via thefirst air channel and a flow of 2.8 l/min at, e.g., 1.6 bar via theVenturi nozzle. The flow is increased to 9 l/min through the Venturinozzle so that all in all the patient is supplied with 15 l/min via thenebulizer mouthpiece. The maximum operation pressure is set via theVenturi nozzle geometry. During an inhalation pause, the bypass channelwould be activated so that the flow of 6 l/min would be redirected viathe bypass channel to the second air channel 5 and still altogether 15l/min would flow to the patient.

FIG. 2 b shows a corresponding circuit diagram for inhalation when thenebulization device is deactivated. While the valve 11 is connected likein the circuit of FIG. 2 a, the valve 10 is a passage for the bypasschannel 9. According to the arrows, the air provided by the compressoris now conveyed via the bypass channel 9 and the air channel 5 into themixing means 3 and provided to the patient exclusively by the latter.The nebulization device is inactive. In order to maintain a constanttotal flow the air flow passed through the bypass channel 9 is conveyedthrough a replacement nozzle 13 having the same properties as thenebulizing nozzle in the nebulization device 2. At the same time thedepicted position of the valve 10 enables an immediate ventilation ofthe nebulization device 2 via a vent duct 14. Thus, it is prevented thata remaining pressure in the air channel 4 may cause a furthernebulization of the active ingredient.

FIG. 2 c shows a corresponding circuit diagram for exhalation. Again,the corresponding air flows are depicted by arrows. The position of thevalve 10 corresponds to that of FIG. 2b. However, the valve 11 isswitched such that the air supplied by the compressor may escapecompletely through a vent. At the same time the connection between theVenturi nozzle or the compressor and the mixing means 3 is interruptedsuch that exhaling into the device is prevented.

FIG. 3 shows an alternative embodiment of the device according to theinvention, wherein the 3/2 valve as shown in FIG. 2 is replaced by a 4/2valve. Thus, the nebulizer can be immediately switched so as not toexert any pressure upon switch-over to the bypass. Furthermore, thevalve 11 has been replaced by a check valve 17 and an additional valve15 is provided directly behind the compressor 1 with a vent duct 16.During the exhalation process the check valve 17 prevents exhaling intothe device, e.g., by a silicone membrane. In this phase of the breathingcycle the compressor 1 is ventilated via the vent duct 16, wherein anozzle is built therein to maintain the operating pressure of thecompressor.

FIG. 4 shows a further embodiment of the invention, wherein noventilation of the nebulizing nozzle is provided. As mentioned above,this means a delayed deactivation of the aerosol generation whereby theadministering of the pharmaceutical can be controlled less precisely.Such an embodiment, however, can nevertheless be taken intoconsideration due to the costs.

A particularly elegant embodiment using only one valve 15 is shown inFIG. 5. The ventilation of both the nebulization device and the entiresystem during exhalation can be effected by means of a single vent duct16. However, therefor a three-step 5/3 valve 15 is required. Further anadditional air channel 18 and two check valves 19 and 20 have to beadded for an appropriate switching.

While the invention is amenable to various modifications and alternativeforms, specific embodiments have been shown by way of example in thedrawings and are described in detail below. The intention, however, isnot to limit the invention to the particular embodiments described. Onthe contrary, the invention is intended to cover all modifications,equivalents, and alternatives falling within the scope of the inventionas defined by the appended claims.

1. A device for providing an aerosol flow, an air flow or bothcomprising: a) at least a compressor for providing an air flow; b) anebulization device for generating an aerosol flow; c) a mixing meansfor optionally mixing the aerosol flow with the air flow to provide atotal flow, wherein the total flow comprises the aerosol flow, air flowor both; d) at least a first air channel arranged between the compressorand the nebulization device; e) at least a second air channel arrangedbetween the compressor and the mixing means; f) at least anamplification device for increasing the air flow provided by thecompressor, and g) a bypass channel connecting the first and the secondair channel and suitable for redirecting the air flow in the first airchannel into the mixing means by bypassing the nebulization device. 2.The device according to claim 1, wherein the amplification meanscomprises at least one or more Venturi nozzles.
 3. The device accordingto claim 2, wherein the Venturi nozzle is arranged along the second airchannel and suitable for introducing ambient air into the second airchannel via a filter.
 4. The device according to claim 2, wherein theVenturi nozzle is operated at 0.5 to 5 bar, at 0.8 to 3 bar, or at 1.2to 2 bar and provides an air flow of 1 to 60 l/min.
 5. The deviceaccording to claim 1, further comprising a control means, wherein theaerosol flow, the air flow or both can be varied or determined by thecontrol means.
 6. The device according to claim 1, wherein the totalflow is substantially temporally constant.
 7. The device according toclaim 1, further comprising a valve, which enables the activation ordeactivation of the bypass channel at certain intervals by maintaining aconstant total flow.
 8. The device according to claim 1, wherein thecompressor and the means for amplification of the air flow are designedsuch that no pressure and/or flow control is necessary.
 9. The deviceaccording to claim 1, wherein the nebulization device generates anaerosol flow of 1 to 20 l/min.
 10. The device according to claim 1,wherein the nebulization device generates an aerosol flow of 3 to 7l/min.
 11. The device according to claim 1, wherein the nebulizationdevice generates an aerosol flow of 6 l/min.
 12. The device according toclaim 1, wherein the total flow is in a range between 1 to 60 l/min. 13.The device according to claim 1, wherein the total flow is in a rangebetween 3 to 30 l/min.
 14. The device according to claim 1, furthercomprising at least a check valve in the second air channel.
 15. Thedevice according to claim 1, further comprising at least a vent valvebetween the compressor and nebulization device.
 16. The device accordingto claim 1, wherein the mixing means is configured as a mouthpiece toenable the use of the device as inhalation device.
 17. The deviceaccording to claim 1, further comprising a tube system for air supply ofinhaled air to the nebulizer and having a tube inner diameter of lessthan 5 mm and a tube length of less than 1.5 m.